Here is the full list of all 19 Race.a.bit achievements.
Unlock all achievements.
Beat a friend on a track you created.
Challenge a friend.
Upload twenty tracks you created.
Race on a hundred community tracks.
Rate fifty community tracks.
Race on fifty community tracks.
Rate twenty community tracks.
Win bronze medals on all official tracks.
Win gold medals on all official tracks.
Win bronze medals on at least half of the official tracks.
Upload ten tracks you created.
Race on ten community tracks.
Rate a community track.
Explode.
Upload a track you created.
Rank in the top 10 of a highscore list.
Fall of the edge.
Win a bronze medal on at least one official track.